Hot stamping, also called press hardening or form hardening, is a relatively young production method within the automotive industry. Because of their strength, hot-stamped components offer very high deformation resistance in the event of a crash. Therefore, particularly components of the kind which are meant not to deform in the event of a crash are hot-stamped. These include, for instance, the A-pillar, B-pillar, bumper cross beam, and side impact bar.
In direct hot stamping a steel blank is austenitized at an elevated temperature, transferred to a cooled die, and deep-drawn to form the desired component. In this way, complex geometries can be formed because the material has excellent formability at high temperatures.
For hot stamping, generally rectangular blanks are heated in a furnace and fed to a press. In the press, each blank acquires via the pressing tool a three-dimensional shape and, if need be, is trimmed already while in the press. Often, however, the component is only subsequently fed to a laser trimming process, since trimming in the tool itself places a heavy load upon the tool. This means that the component must be removed from the press and fed to a further processing station, namely the laser cutting station. Alternatively, it is known to trim the plates for the hot forming process prior to their introduction into the tool.
In industrial production, rolls or stacks of materials are processed and transformed with a wide variety of different cutting and deforming tools into structured components. For the processing, laser cutting systems are used to generate the desired shapes and cutouts. The material is machined on a work rest, which constitutes a flat base surface for the cutting or deforming tool.
DE 10 2004 034 256 B4 discloses an apparatus for cutting sheet metal. A metal band is transported in a transport direction by means of a conveyor. The conveyor has two transport devices arranged in succession in the direction of transport. An opening is formed between two mutually opposite ends of the transport devices. The mutually opposite ends of the transport devices can be moved in the same direction, either in or counter to the direction of transport. Consequently, the opening can thus be shifted in or counter to the direction of transport. Above the opening is found a laser cutting device, the laser beam of which is constantly directed at the opening. In order to produce a chosen cut in a metal band transported on the conveyor, the laser cutting device can be moved both in an X-direction corresponding to the direction of transport and perpendicularly thereto in a Y-direction. The opening is here always moved concurrently with the laser beam. In order to create a plurality of different contour cuts, a plurality of laser cutting apparatuses of this type may also be arranged along the conveyor at a distance apart. A similar apparatus is also known from WO 2010/085486 A1.
These known laser cutting systems process plates at a cycle rate of about ten plates per minute. Should it be desired to make the hot stamping efficient, this cycle rate is too low. The use of laser cutting systems for the prefabrication of plates for hot stamping is not therefore widespread.
It would be beneficial to provide a system and method that overcomes at least some of the above-mentioned limitations.